Catheter system for repairing a mitral valve annulus

ABSTRACT

A catheter system and methods for repairing a valvular annulus or an annular organ structure of a patient comprising sandwiching and compressing the annulus and applying heat sufficient to shrink or tighten tissue surrounding the annulus defect.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of application Ser. No.10/083,264, filed on Oct. 22, 2001, which is a continuation-in-part ofapplication Ser. No. 09/410,902 filed Oct. 2, 1999, now U.S. Pat. No.6,306,133, all of which are incorporated by reference herein in itsentirety.

FIELD OF THE INVENTION

The present invention generally relates to a system and methods forapplying therapeutic energy to a patient for medical purposes such asreducing and/or shrinking a tissue mass. More particularly, theinvention relates to an ablation catheter system that selectivelycontacts the tissue of a valvular annulus in order to tighten andstabilize an annular organ structure adapted for repairing an annularorgan structure defect of a patient.

BACKGROUND OF THE INVENTION

The circulatory system consists of a heart and blood vessels. In itspath through the heart, the blood encounters four valves. The valve onthe right side that separates the right atrium from the right ventriclehas three cusps and is called the tricuspid valve. It closes when theventricle contracts during a phase known as systole and it opens whenthe ventricle relaxes, a phase known as diastole.

The pulmonary valve separates the right ventricle from the pulmonaryartery. It opens during systole, to allow the blood to be pumped towardthe lungs, and it closes during diastole to keep the blood from leakingback into the heart from the pulmonary artery. The pulmonary valve hasthree cusps, each one resembling a crescent and it is also known as asemi-lunar valve.

The mitral valve, so named because of its resemblance to a bishop'smitre, is in the left ventricle and it separates the left atrium fromthe ventricle. It opens during diastole to allow the blood stored in theatrium to pour into the ventricle, and it closes during systole toprevent blood from leaking back into the atrium. The mitral valve andthe tricuspid valve differ significantly in anatomy. The annulus of themitral valve is somewhat D-shaped whereas the annulus of the tricuspidvalve is more nearly circular.

The fourth valve is the aortic valve. It separates the left ventriclefrom the aorta. It has three semi-lunar cusps and it closely resemblesthe pulmonary valve. The aortic valve opens during systole allowing astream of blood to enter the aorta and it closes during diastole toprevent any of the blood from leaking back into the left ventricle.

In a venous circulatory system, a venous valve is to prevent the venousblood from leaking back into the upstream side so that the venous bloodcan return to the heart and the lungs for blood oxygenating purposes.

Clinical experience has shown that repair of a valve, either a heartvalve or a venous valve, produces better long-term results than doesvalve replacement. Valve replacement using a tissue valve sufferslong-term calcification problems. On the other hand, anticoagulationmedicine, such as heparin, is required for the life of a patient when amechanical valve is used in valve replacement. The current technologyfor valve repair or valve replacement requires an expensive open-heartsurgery that needs a prolonged period of recovery. A less invasivecatheter-based valve repair technology becomes an unmet clinicalchallenge.

The effects of valvular dysfunction vary. Mitral regurgitation has moresevere physiological consequences to the patient than does tricuspidvalve regurgitation. In patients with valvular insufficiency it is anincreasingly common surgical practice to retail the natural valve, andto attempt to correct the defects. Many of the defects are associatedwith dilation of the valve annulus. This dilatation not only preventscompetence of the valve but also results in distortion of the normalshape of the valve orifice or valve leaflets. Remodeling of the annulusis therefore central to most reconstructive procedures for the mitralvalve.

As a part of the valve repair it is either necessary to diminish orconstrict the involved segment of the annulus so that the leaflets maycoapt correctly on closing, or to stabilize the annulus to preventpost-operative dilatation from occurring. The current open-heartapproach is by implantation of a prosthetic ring, such as a CosgroveRing or a Carpentier Ring, in the supra annular position. The purpose ofthe ring is to restrict and/or support the annulus to correct and/orprevent valvular insufficiency. In tricuspid valve repair, constrictionof the annulus usually takes place in the posterior leaflet segment andin a small portion of the adjacent anterior leaflet.

Various prostheses have been described for use in conjunction withmitral or tricuspid valve repair. The ring developed by Dr. AlainCarpentier (U.S. Pat. No. 3,656,185) is rigid and flat. An open ringvalve prosthesis as described in U.S. Pat. No. 4,164,046 comprises auniquely shaped open ring valve prosthesis having a special velourexterior for effecting mitral and tricuspid annuloplasty. The fullyflexible annuloplasty ring could only be shortened in the posteriorsegment by the placement of placating sutures. John Wright et al. inU.S. Pat. No. 5,674,279 discloses a suturing ring suitable for use onheart valve prosthetic devices for securing such devices in the heart orother annular tissue. All of the above valve repair or replacementrequires an open-heart operation which is costly and exposes a patientto higher risk and longer recovery than a catheter-based less invasiveprocedure.

Moderate heat is known to tighten and shrink the collagen tissue asillustrated in U.S. Pat. No. 5,456,662 and U. S. Pat. No. 5,546,954. Itis also clinically verified that thermal energy is capable of denaturingthe tissue and modulating the collagenous molecules in such a way thattreated tissue becomes more resilient (“The Next Wave in MinimallyInvasive Surgery” MD&DI pp. 36-44, August 1998). Therefore, it becomesimperative to treat the inner walls of an annular organ structure of aheart valve, a valve leaflet, chordae tendinae, papillary muscles, andthe like by shrinking/tightening techniques. The sameshrinking/tightening techniques are also applicable to stabilizeinjected biomaterial to repair the defect annular organ structure,wherein the injectable biomaterial is suitable for penetration andheat-initiated shrinking/tightening.

One method of reducing the size of tissues in situ has been used in thetreatment of many diseases, or as an adjunct to surgical removalprocedures. This method applies appropriate heat to the tissues, andcauses them to shrink and tighten. It can be performed on a minimalinvasive fashion, which is often less traumatic than surgical proceduresand may be the only alternative method, wherein other procedures areunsafe or ineffective. Ablative treatment devices have an advantagebecause of the use of a therapeutic energy that is rapidly dissipatedand reduced to a non-destructive level by conduction and convection, toother natural processes.

Radiofrequency (RF) therapeutic protocol has been proven to be highlyeffective when used by electrophysiologists for the treatment oftachycardia, atrial flutter and atrial fibrillation; by neurosurgeonsfor the treatment of Parkinson's disease; by otolaryngologist forclearing airway obstruction and by neurosurgeons and anesthetists forother RF procedures such as Gasserian ganglionectomy for trigeminalneuralgia and percutaneous cervical cordotomy for intractable pains.Radiofrequency treatment, which exposes a patient to minimal sideeffects and risks, is generally performed after first locating thetissue sites for treatment. Radiofrequency energy, when coupled with atemperature control mechanism, can be supplied precisely to thedevice-to-tissue contact site to obtain the desired temperature fortreating a tissue or for effecting the desired shrinking of the hostcollagen or injected biomaterial adapted to immobilize the biomaterialin place.

Edwards et al. in U.S. Pat. No. 6,258,087, entire contents of which areincorporated herein by reference, discloses an expandable electrodeassembly comprising a support basket formed from an array of spines forforming lesions to treat dysfunction in sphincters. Electrodes carriedby the spines are intended to penetrate the tissue region upon expansionof the basket. However, the assembly disclosed by Edwards et al. doesnot teach a tissue-contactor member comprising a narrow middle regionbetween an enlarged distal region and an enlarged proximal regionsuitable for sandwiching and compressing the sphincter for tissuetreatment.

Tu in U.S. Pat. No. 6,267,781 teaches an ablation device for treatingvalvular annulus or valvular organ structure of a patient, comprising aflexible elongate tubular shaft having a deployable spiral wireelectrode at its distal end adapted to contact/penetrate the tissue tobe treated and to apply high frequency energy to the tissue fortherapeutic purposes. Tu et al. in U.S. Pat. No. 6,283,962 discloses amedical ablation device system for treating valvular annulus wherein anelongate tubular element comprises an electrode disposed at its distalsection that is extendible from an opening at one side of the tubularelement, the energy generator, and means for generating rotationalsweeping force at the distal section of the tubular element to effectthe heat treatment and the rotational sweeping massage therapy fortarget tissues. Both patents, entire contents of which are incorporatedherein by reference, teach only the local tissue shrinkage, not fortreating simultaneously a substantial portion of the valvular annulus.

Therefore, there is a clinical need to have a less invasivecatheter-based approach for repairing an annular organ structure of aheart valve, a valve leaflet, chordae tendinae, papillary muscles, andthe tissue defect by using high frequency energy for reducing and/orshrinking a tissue mass, with optionally an injected biomaterial alongwith the host tissue mass for tightening and stabilizing the dilatedtissue adjacent a valvular annulus.

SUMMARY OF THE INVENTION

In general, it is an object of the present invention to provide acatheter system and methods for repairing an annular organ structure ofa heart valve, an annular organ structure of a venous valve, a valveleaflet, chordae tendinae, papillary muscles, a sphincter, and the like.

It is another object of the present invention to provide a cathetersystem and methods by using high frequency current for tissue treatmentor repairing and causing the tissue to shrink or tighten.

It is still another object to provide a catheter-based less invasivesystem that contacts the tissue of an annulus in order to tighten andstabilize a substantial portion of the dysfunctional annular organstructure simultaneously or sequentially.

It is a preferred object to provide a method for repairing a valvularannulus defect comprising injecting a heat shapeable biomaterialformulated for in vivo administration by injection via a delivery systemat a site of the valvular annulus defect; and applying heat sufficientto shape the biomaterial and immobilize the biomaterial at about theannulus defect.

It is another preferred object of the present invention to provide aflexible tissue-contactor member located at the distal tip section of acatheter shaft for compressively sandwiching and contacting an innerwall of an annular organ structure, wherein the tissue-contactor memberincludes an expandable structure having a narrow middle region andenlarged end regions that is generally configured to snugly fit andsandwich the inner wall of an annular organ structure for optimaltherapy that is characterized by exerting compression onto the innerwall.

It is another object of the invention to provide a method for repairinga tissue defect comprising: injecting a heat shapeable biomaterialformulated for in vivo administration by injection via a percutaneousdelivery system at a site of the tissue defect; and applying heat to thebiomaterial and a portion of the tissue defect adapted for shaping thebiomaterial, the heat being below a temperature sufficient for effectingcrosslinking of the biomaterial and the portion of the tissue defect.

It is still another object of the present invention to provide acatheter system and methods for providing high frequency current energyto the tissue needed for treatment at or adjacent an annular organstructure.

In one embodiment, the method for operating a catheter system forrepairing a valvular annulus or a valveless annulus comprisingcompressively sandwiching the annulus by a tissue-contactor member anddelivering high frequency energy to the annulus, wherein thetissue-contactor member is configured to have a narrow middle regionbetween an enlarged distal region and an enlarged proximal regionadapted for compressively sandwiching the annulus at about the middleregion for subsequent tissue treatment.

The catheter system of the present invention has several significantadvantages over known catheters or ablation techniques for repairing anannular organ structure of a heart valve, a valve leaflet, chordaetendinae, papillary muscles, venous valve, and the like. In particular,the ablation catheter of this invention by using high frequency currentenergy for reducing and/or shrinking a tissue mass may tighten andstabilize the dilated tissue at or adjacent a valvular annulus.

BRIEF DESCRIPTION OF THE DRAWING

Additional objects and features of the present invention will becomemore apparent and the invention itself will be best understood from thefollowing Detailed Description of the Exemplary Embodiments, when readwith reference to the accompanying drawings.

FIG. 1 is an overall view of a catheter system having a flexibletissue-contactor member and electrode element means at its distal tipsection constructed in accordance with the principles of the presentinvention.

FIG. 2 is a close-up view of the distal tip section of the cathetersystem comprising a retracted tissue-contactor members with a retractedelectrode element means at a non-deployed state.

FIG. 3 is a close-up view of the distal tip section of the cathetersystem comprising a deployed tissue-contactor member having a retractedelectrode element means.

FIG. 4 is a front cross-sectional view, section I—I of FIG. 3, of thedistal tip section of a catheter system comprising a deployedtissue-contactor member.

FIG. 5 is a close-up view of the distal tip section of the cathetersystem comprising a deployed tissue-contactor member and a deployedelectrode element means at a fully deployed state.

FIG. 6 is a front cross-sectional view, section II—II of FIG. 5, of thedistal tip section of a catheter system comprising a deployedtissue-contactor member with a deployed electrode element means.

FIG. 7 is a simulated view of the catheter system of the presentinvention in contact with the tissue of an annular organ structure.

FIG. 8 is a first preferred embodiment of a catheter system having adeployed flexible tissue-contactor member and electrode element means atits distal tip section constructed in accordance with the principles ofthe present invention.

FIG. 9 is a detailed cross-sectional view of the distal tip section ofthe catheter system according to the first preferred embodiment in FIG.8, comprising a deployed tissue-contactor member for treating the tissueof an annular organ structure.

FIG. 10 is a second preferred embodiment of a catheter system having adeployed flexible tissue-contactor member and electrode element means atits distal tip section constructed in accordance with the principles ofthe present invention.

FIG. 11 is a first step of deploying a tissue-contactor member of thecatheter system according to the second preferred embodiment in FIG. 10for treating the tissue of an annular organ structure.

FIG. 12 is a second step of deploying a tissue-contactor member of thecatheter system according to the second preferred embodiment in FIG. 10for treating the tissue of an annular organ structure.

FIG. 13 is a third step of deploying a tissue-contactor member of thecatheter system according to the second preferred embodiment in FIG. 10for treating the tissue of an annular organ structure.

FIG. 14 is a third preferred embodiment of a catheter system having adeployed flexible tissue-contactor member and electrode element means atits distal tip section constructed in accordance with the principles ofthe present invention.

FIG. 15 is a detailed cross-sectional view of the distal tip section ofthe catheter system according to the third preferred embodiment in FIG.14, comprising a deployed tissue-contactor member for treating thetissue of an annular organ structure.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The following descriptions of the preferred embodiment of the inventionare exemplary, rather than limiting, and many variations andmodifications are within the scope of the invention. What is shown inFIGS. 1 to 15 is an embodiment of the present invention to provide acatheter system that selectively contacts the tissue of an annulus inorder to tighten and stabilize an annular organ structure adapted forrepairing an annular organ structure defect of a patient.

“Sandwich” as a verb is herein meant to make into between usually twothings of another quality or character; particularly intended to meanconfining an annulus between two radially enlarged end regions of atissue-contactor member characterized by certain degrees of compressiononto the annulus exerted from the two end regions.

It is one object of the present invention to provide a method forrepairing a valvular annulus defect comprising injecting a heatshapeable biomaterial formulated for in vivo administration by injectionvia a delivery system at a site of the valvular annulus defect; andapplying heat sufficient to shape the biomaterial and immobilize thebiomaterial at about the annulus defect.

FIG. 1 shows an overall view of one embodiment of a catheter-basedhigh-frequency treatment system having a flexible tissue-contactormember and an electrode element means at its distal tip sectionconstructed in accordance with the principles of the present invention.A catheter system constructed in accordance with the principles of thepresent invention comprises a flexible catheter shaft 1 having a distaltip section 2, a distal end 3, a proximal end 4, and at least one lumen14 extending therebetween.

In one embodiment, the catheter system comprises a flexible, relativelysemi-rigid tissue-contactor member 5 located at the distal tip section 2and inside the at least one lumen 14 of the catheter shaft 1 forcontacting an inner wall 51 of an annular organ structure 52 whendeployed. The tissue-contactor members may have certain variations (35in FIG. 8 and 45 in FIG. 10) sharing the common characteristics ofhaving a narrow middle region between a first radially enlarged proximalregion and a second radially enlarged distal region suitable forcompressively sandwiching the inner wall 51 of the annular organstructure 52 for effectively applying tissue-shrinkable energysite-specifically. It is believed that “compressively sandwiching theinner wall of the annular organ structure” is a significant requirementand one particular embodiment of the present invention for effectivelyapplying tissue-shrinkable energy site-specifically.

The tissue-contactor member 5 is deployable out of the at least onelumen 14 by a tissue-contactor deployment mechanism 15 located at ahandle 7. The tissue-contactor member 5 is preformed or expandable tohave an appropriate shape configured to fit with the inner wall 51 ofthe annular organ structure 52. The tissue-contactor member 5 may beselected from the group consisting of a circular ring, a D-shaped ring,a kidney-shaped ring, an oval ring, and other round-shaped construct.

The handle 7 is attached to the proximal end 4 of the catheter shaft 1.The handle comprises the tissue-contactor deployment mechanism 15 and anelectrode deployment means 16 for advancing the electrode element means9 out of the tissue-contactor member 5. The electrode element meansintended for shrinking tissue of an annular organ structure may compriseneedle electrodes 9 in FIG. 6, or other variations such as the one madeof conductive elastomer material on a balloon (37, 38, 39 in FIG. 9) ora basket electrode element 48 in FIG. 13.

A connector 8 secured at the proximal end of the catheter system, ispart of the handle section 7. The handle has one optional steeringmechanism 10. The steering mechanism 10 is to deflect the distal tipsection 2 of the catheter shaft 1 for catheter maneuvering andpositioning. In one preferred embodiment, by pushing forward the frontplunger 11 of the handle 7, the distal tip section 2 of the cathetershaft deflects to one direction. By pulling back the front plunger 11,the tip section returns to its neutral position. In another embodiment,the steering mechanism 10 at the handle 7 comprises means for providinga plurality of deflectable curves on the distal tip section 2 of thecatheter shaft 1.

The catheter system also comprises a high frequency current generator61, wherein an electrical conductor means 62 for transmitting highfrequency current to the electrode element means (9 in FIG. 1, 35 inFIG. 8 or 45 in FIG. 10) is provided. One object of the presentinvention is to provide high frequency heat to collagen of tissue to atemperature range of about 45° C. to 75° C. or higher for at least a fewseconds to cause collagen to shrink a fraction of its originaldimension. The energy required from the high frequency current generatoris generally less than 100 watts, preferably less than 10 watts.

The high frequency current may be selected from a group consisting ofradiofrequency current, microwave current, ultrasound current, andcombination thereof. Tu in U.S. Pat. No. 6,235,024, entire contents ofwhich are incorporated herein by reference, discloses a catheter systemhaving dual ablation capability of ultrasound current and radiofrequencycurrent. The electrode element of the present invention may comprise aradiofrequency electrode, an ultrasound electrode (that is, transducer)or a combination thereof.

In one embodiment, the method may comprise percutaneously introducingthe catheter system through a blood vessel to a site of the valvularannulus or introducing the catheter system through a thoroscopy portinto a heart or injecting the heat shapeable biomaterial during anopen-heart surgery. For other applications such as the sphinctertreatment, the catheter may be introduced through a natural opening ofthe body. The application for sphincter treatment of the presentinvention comprises esophageal sphincter, urinary sphincter or the like.Small, ring-like muscles, called sphincters, surround portions of thealimentary canal. In a healthy person, these muscles contract or tightenin a coordinated fashion during eating and the ensuing digestiveprocess, to temporarily close off one region of the alimentary canalfrom another.

For example, a muscular ring called the lower esophageal sphinctersurrounds the opening between the esophagus and the stomach. The loweresophageal sphincter is a ring of increased thickness in the circular,smooth-muscle layer of the esophagus. Normally, the lower esophagealsphincter maintains a high-pressure zone between fifteen and thirty mmHg above intragastric pressures inside the stomach. The catheter systemand methods of the present invention may suitably apply to repair asphincter annulus, other than the esophageal sphincter, in a patient.

FIG. 2 shows a close-up view of the distal tip section 2 of the cathetersystem comprising a retracted tissue-contactor member 5 with a retractedelectrode element means 9 at a non-deployed state. Both thetissue-contactor member and the electrode element means are retractableto stay within the at least one lumen 14. This non-deployed state isused for a catheter to enter into and to withdraw from the body of apatient. The tissue-contactor member is generally preformed orconstricted and flexible enough so that it can easily be retracted intothe catheter lumen 14.

The tissue-contactor member 5 may be made of a biocompatible materialselected from the group consisting of silicone, latex, polyurethane,fluoro-elastomer, polypropylene, polyethylene, polyethyleneterephthalate, nylon, and a combination thereof. Reinforced substrate,such as mesh, wire, fiber, and the like, may be added to thetissue-contactor member 5 to make the tissue-contactor member semi-rigidso that when it is deployed, adequate pressure is exerted to thesurrounding tissue for stabilizing its placement.

In one particular embodiment, the catheter system may comprise a needleelectrode element means 9 located at or within the flexibletissue-contactor member 5 for penetrating into a tissue, such as aninner wall 51, wherein the needle electrode element means 9 isdeployable out of the tissue-contactor member 5 in a manner essentiallyperpendicular to a longitudinal axis of the catheter shaft 1 when theneedle electrode element means is deployed. In another preferredembodiment, the angle of the needle electrode against a tissue may beany suitable angle from 30 degrees to 150 degrees in reference to alongitudinal axis of the catheter shaft for effective tissuepenetration.

The needle electrode element means 9 may comprise a plurality of needleelectrodes 9A, 9B, 9C (shown in FIG. 6) that are preshaped to beessentially perpendicular to a longitudinal axis of the catheter shaft 1when deployed. The high frequency current may be delivered to each ofthe plurality of needle electrodes 9A, 9B, 9C in a current delivery modeselected from the group consisting of individual delivery mode, pulseddelivery mode, sequential delivery mode, simultaneous delivery mode or apre-programmed mode. The needle electrode element means 9 may be made ofa material selected from the group consisting of platinum, iridium,gold, silver, stainless steel, tungsten, Nitinol, and other conductingmaterial. The needle electrode element means 9 is connected to anelectrode deployment means 16 at the handle 7 for advancing one or moreneedles of the needle electrode element means 9 out of thetissue-contactor member 5. This electrode deployment means may includevarious deployment modes selected from a group consisting of a singleneedle electrode deployment, a plurality of needle electrodes deploymentor an all needle electrodes simultaneous deployment.

The “tissue-contactor member” in this invention is intended to mean aflexible semi-rigid element adapted for contacting an inner wall of anannular organ structure of a patient and is also preformed to have anappropriate shape compatible with the inner wall of the annular organstructure. The tissue-contactor member 5 may generally comprise aplurality of grooves or internal channels 25 (as shown in FIG. 4) sothat a needle electrode of the needle electrode element means is able todeploy out of and retract into the tissue contactor means with minimalfrictional resistance.

FIG. 3 shows a close-up view of the distal tip section 2 of oneembodiment of the catheter system comprising a deployed tissue-contactormember 5 and a retracted needle electrode element means 9. The outerdiameter of the deployed tissue-contactor member 5 is optionally largerthan the outer diameter of the catheter shaft 1 so that the outer rim 12of the deployed tissue-contactor member may stably stay on the innerwall of the annular organ structure. A supporting member 21 along with aplurality of auxiliary supporting members 22 secured at the distal endof the supporting member 21 form a connecting means for connecting thetissue-contactor member 5 to the tissue-contactor deployment mechanism15 that is located on the handle 7. The supporting member 21 and itsauxiliary supporting members 22 are located within the at least onelumen 14 and have suitable torque transmittable property and adequaterigidity for deploying the tissue-contactor member 5.

The needle electrode of the first embodiment is preferably made ofconductive material, while the surfaces of the catheter shaft 1,conducting wires 62, the supporting member 21 along with its auxiliarysupporting members 22, are preferably covered/coated with an insulatingmaterial or electrically insulated.

In one preferred embodiment, the needle electrode is hollow with a fluidconduit connected to an external fluid source having a fluid injectionmechanism. By “fluid” is meant an injectable shapeable biomaterial thatis formulated for in vivo administration by injection via a deliverysystem at a site of the valvular annulus defect or tissue defect. By“tissue defect” is meant vulnerable plaque, calcified tissue, valvularannulus defect, annular defect, or other lesions of atherosclerosis.

FIG. 4 shows a front cross-sectional view; section I—I of FIG. 3, of thedistal tip section of a catheter system comprising a deployedtissue-contactor member 5. The tissue-contactor member of the presentinvention in different improved embodiments adapted for serving the sameindications of repairing tissue of an annular organ structure maycomprise a plurality of open channels 24, pores and the like for a fluidor blood to pass from a proximal end of the tissue-contactor member to adistal end of the tissue-contactor member. The open channels may includemacropores, micropores, openings, or combination thereof.

FIG. 5 shows a close-up view of the distal tip section 2 of oneembodiment of the current catheter system comprising a deployedtissue-contactor member 5 and a deployed needle electrode elements 9A,9B at a fully deployed state. The fully deployed state is used fordelivery of high frequency current energy to the needle electrodeelements 9A, 9B and subsequently to the site-specific contact tissue forrepairing the annular organ structure. The delivery of high frequencycurrent to each of the needle electrode elements may go through asplitter or other mechanism. The needle electrode element means 9 ispreformed so that when deployed, the needle electrodes are in a manneressentially perpendicular to a longitudinal axis of the catheter shaft 1or at a suitable angle for effective thermal therapy.

FIG. 6 shows a front cross-sectional view, section II—II of FIG. 5, ofthe distal tip section 2 of a catheter system comprising a deployedtissue-contactor member 5 and a deployed needle electrode element means9. The tips of the needle electrodes 9A, 9B, and 9C extend out of therim 12 of the tissue-contactor member 5 and penetrate into tissue forenergy delivery.

FIG. 7 shows a simulated view of the catheter system of the presentinvention in contact with the tissue 51 of an annular organ structure52. The heart 70 has a left atrium 71, a left ventricle 72, a rightventricle 73, and a right atrium 74. Aorta 75 connects with the leftventricle 72 and contains an aorta valve 76. Pulmonary artery 77connects with the right ventricle 73 through a pulmonary valve. Leftatrium 71 communicates with the left ventricle 72 through a mitral valve79. The right atrium 74 communicates with the right ventricle 73 througha tricuspid valve 80. Oxygenated blood is returned to the heat 70 viapulmonary veins 88. In a perspective illustration, a catheter isinserted into the right atrium 74 and is positioned on the inner wall 51of the tricuspid valve 80. The leaflets of the tricuspid valve 80 opentoward the ventricle side. Blood returned from the superior vena cava 84and the opposite inferior vena cava flows into the right atrium 74.Subsequently, blood flows from the right atrium 74 to the rightventricle 73 through the tricuspid valve 80. Therefore, thetissue-contactor member 5 of the catheter shaft 1 does not interferewith the leaflet movement during the proposed less invasive thermaltherapy of the invention.

FIG. 8 shows a first preferred embodiment of a catheter system having aflexible tissue-contactor member 35 and electrode element means at itsdistal tip section 2 constructed in accordance with the principles ofthe present invention. As disclosed in the current invention, thetissue-contactor member 35 is retracted within one of the at least onelumen 14 during catheter insertion into and removal from the patient.

FIG. 9 shows a detailed cross-sectional view of the distal tip section 2of the catheter system according to FIG. 8, comprising a deployedtissue-contactor member 35 for treating the tissue of an annular organstructure. In a first preferred embodiment, the tissue-contactor member35 may comprise a “double-mound” shaped balloon made of flexibleexpandable biocompatible material selected from a group consisting ofsilicone, latex, polyurethane, fluoro-elastomer, polypropylene,polyethylene, polyethylene terephthalate, nylon, and a combinationthereof. The “double-mound” shape structure of the tissue-contactormember 35 or 45 is related generally to a structure that thetissue-contactor member is deployable out of the lumen of a cathetershaft and is expandable upon deployment configured to have a narrowmiddle region between an enlarged distal region and an enlarged proximalregion (the so-called “double-mound” structure) suitable forcompressively sandwiching the inner wall of the annular organ structure.The basic principle for the tissue-contactor member (such as 5 in FIG.1, 35 in FIG. 8, 45 in FIG. 10, or 95 in FIG. 14) of the presentinvention is to compress the target tissue (annulus, sphincter, tumorand the like) for enhanced heat shrinkage/tightening on tissue. Thecompression may come from sandwich-type setup, such as from two oppositeelements with the target tissue in between or from two elements at asuitable angle arrangement to compress the target tissue. In anotherembodiment, the “compressively sandwiching” a tissue is also hereinintended to mean compression from two elements at a suitable anglearrangement to compress the target tissue as shown by two pairs ofelectrode elements (FIG. 15): the first electrode elements 96compressing forwardly toward the distal end 53 and the second electrodeelements 98 compressing radially toward the side of the target tissue.

In one illustrative example, the tissue-contactor member 35 in FIG. 9 asan expanded balloon comprises a radially enlarged proximal region 87, amiddle region 85, and a radially enlarged distal region 86. Thetechniques to inflate and deflate a balloon 36 by infusing physiologicalliquid through a liquid passageway within the lumen 54 and the infusionopening 31 are well known to one who is skilled in the art and do notform a part of the present invention. The tissue-contactor member 35 maycomprise a plurality of flexible electrode elements, wherein theelectrode elements may be grouped 37, 38 or 39 for performing variousmodes of energy delivery selected from the group consisting ofindividual mode, pulsed mode, programmed mode, simultaneous mode, orcombination thereof. The flexible electrode elements 37, 38, 39 may bemade of conductive elastomer material or metal-containing conductiveelastomer material selected from the group consisting of silicone,latex, polyurethane, fluoro-elastomer, nylon, and a combination thereof.The flexible electrode elements normally have similar expansioncoefficient as that of the base balloon material and are securely bondedto the surface of the balloon 36 at appropriate locations so that eachelectrode becomes an integral part of the general tissue-contractormember 35. In the first embodiment, the balloon 36 may have anessentially hyperbolic shape with a neck region adapted for positioningthe neck region at about the inner wall of the annular organ structure,wherein the plurality of electrode elements (37, 38 or 39 in FIG. 9) arepositioned at about the neck region.

FIG. 10 shows a second preferred embodiment of a catheter systemcomprising a flexible tissue-contactor member 45 having electrodeelement means at its distal tip section 2 constructed in accordance withthe principles of the present invention. The steps for deploying thetissue-contactor member 45 are shown in FIGS. 11 to 13. FIG. 11 shows afirst step of deploying a tissue-contactor member 45 of the cathetersystem 1 according to the second preferred embodiment in FIG. 10 fortreating the tissue of an annular organ structure. The flexibletissue-contactor member 45 comprises a proximal balloon 46 as theenlarged proximal region, the distal balloon 47 as the enlarged distalregion, and a basket electrode element means 48 as the middle region.The outer diameter of the basket electrode element means 48 of themiddle region is smaller than that of either enlarged end region 46, 47so that the annulus is “compressively sandwiched” for tissue treatment.

The techniques to inflate and deflate a balloon 46 or 47 by infusingphysiologic liquid through the liquid passageway 41 or 44 inside a lumen55 are well known to one who is skilled in the art and do not form apart of the present invention. Other types of balloons, such asdouble-balloon, porous balloon, microporous balloon, channel balloon orthe like that meet the principles of the present invention may beequally herein applicable.

After the first balloon 46 is inflated and sits appropriately at theupstream side of the annulus, a second balloon 47 is also inflatedsubsequently. At this moment of operations, the annulus of the annularorgan structure is positioned loosely between the two end balloons 46and 47. By relaxing or compressing axially the middle sectiontherebetween (indicated by the arrows 49 in FIG. 12), the annulus is“compressively sandwiched” as defined in the present invention. A“sandwiched” annulus of the present invention generally exhibits certaindegree of tightness or compressing.

FIG. 13 shows a third step of deploying a tissue-contactor member 45 ofthe catheter system according to the second preferred embodiment in FIG.10 for treating the tissue of an annular organ structure, comprisingdeployment of the electrode element means 48. The electrode elementmeans 48 may comprise a plurality of basket members that are expandableradially outwardly with a conductive surface 43 on each basket memberfacing outwardly. Other surface areas of the basket members away fromthe conductive surface 43 are insulated and not conductive. As disclosedand well known to a skilled artisan, an electrical conductor means 62for transmitting high frequency current from a high frequency currentgenerator 61 to the electrode elements 48 is provided.

In a preferred embodiment, a method for operating a catheter system ofthe present invention for repairing a valvular annulus, the method maycomprise: (a) percutaneously introducing the catheter system through ablood vessel to a site of the valvular annulus or introducing thecatheter system through a thoroscopy port into a heart or optionallyinjecting the heat shapeable biomaterial during an open heart surgery;(b) positioning the tissue-contactor member of the catheter shaft on theinner wall of the valvular annulus; (c) advancing the electrode elementsfor contacting the electrode elements with tissue of the valvularannulus; (d) optionally injecting heat shapeable biomaterial at the siteof the valvular annulus defect; and (e) applying high frequency currentthrough the electrical conductor means to the electrode elements forrepairing the valvular annulus defect.

FIG. 14 shows a third preferred embodiment of a catheter system having adeployed flexible tissue-contactor member 95 and electrode element meansat its distal tip section constructed in accordance with the principlesof the present invention. The acorn-shaped tissue-contactor member 95 isto compressively sandwich a target annulus from two sides of the annulusat about 90 degrees to each other.

FIG. 15 shows a detailed cross-sectional view of the distal tip section2 of the catheter system 1 according to the third preferred embodimentin FIG. 14, comprising a deployed tissue-contactor member 95 fortreating the tissue of an annular organ structure. In an example ofmitral annulus treatment for illustration purposes, the first balloon 91is intended to lay on top of the annulus while the flexible electrodeelements 96 made of conductive elastomer material are intended toprovide sufficient therapeutic energy for treating the annulus. Thesecond balloon 59 is intended to lay against the inner wall of theannulus so that the flexible electrode elements 98 made of conductiveelastomer material are intended to provide sufficient therapeutic energyfor treating the leaflets. As is well known to one who is skilled in theart of balloon construction and the high frequency ablation technology,an electrical conductor means 97 or 99 for transmitting high frequencycurrent to each electrode 96 or 98 is provided individually to theenergy source while physiologic liquid to each balloon 91, 59 through aliquid passageway 92, 93 is also provided.

In an alternate embodiment, the flexible electrode elements 96, 98 maycomprise a plurality of discrete elements, a plurality of contiguouselements, or a plurality of discrete element groups, each groupcomprising at least one electrode element. The arrangement of differentstyles of electrode elements is to facilitate treating a desired portionor a complete annular tissue under various modes. It is also well knownto one skilled in the art that the flexible electrode means of thepresent invention may be constructed of an elongate flexible conductiveelectrode or with a conductive surface. In one example, an elongateflexible conductive electrode may comprise a metal-containing elastic(stretchable) electrode made of similar constructing material of theballoon. In a further embodiment, the elongate flexible conductiveelectrode may be a separate conductive elastic band (like a party rubberband) that is deployed between the exterior surface of the balloon andthe inner wall of the annulus.

One advantage of the current embodiment in FIG. 15 is to providephysiologic liquid to inflate a balloon for repairing the valvulardefect, whereas the liquid in the balloon serves as a heat sink todissipate the heat generated from the high frequency electrode elementscontacting the tissue. By continuously diverting the excess heat fromthe electrode-tissue contact site, the treatment efficiency can besubstantially enhanced to cause quality desired shrinkage or tighteningof the tissue of the annulus. The requirement for the high frequencypower can therefore be significantly reduced. The energy required fromthe high frequency current generator is generally less than 100 watts intissue ablation, preferably less than 10 watts because of theheat-dissipating embodiment of the present invention for repairing anannulus.

The catheter system of the present invention may also comprise aguidewire adaptive mechanism, such as a guidewire channel 94 located atabout the balloon distal end 53 in FIG. 15 for the catheter to ride on aguidewire to the desired location for tissue treatment.

In one embodiment, a method for operating a catheter system forrepairing an annulus comprises compressively sandwiching the annulus bya tissue-contactor member having electrode elements and delivering highfrequency energy at or near the annulus through the electrode elements.Further, the method for repairing an annulus having valvular leafletsfurther comprises delivering high frequency energy to the leaflets.

In another preferred embodiment, a method for operating a cathetersystem for repairing an annulus may comprise compressively sandwichingthe annulus by a tissue-contactor member and delivering high frequencyenergy to the annulus, wherein the tissue-contactor member is configuredto have a narrow middle region between a radially enlarged distal regionand a radially enlarged proximal region. In a further embodiment, themethod for operating a catheter system for repairing an annuluscomprises: (a) introducing the catheter system of the present inventionthrough a bodily opening to an annulus; (b) deploying thetissue-contactor member of the catheter shaft at about the inner wall ofthe annulus; (c) positioning the electrode elements so as to enable theelectrode elements contacting said inner wall of the annulus; and (d)applying high frequency current through the electrical conductor meansto the electrode elements for repairing the annulus.

The tissue of the heart valve in the procedures may be selected from thegroup consisting of valvular annulus, chordae tendinae, valve leaflet,and papillary muscles. The high frequency current in the procedures maybe selected from the group consisting of radiofrequency current,microwave current, ultrasound current, and combination thereof.

A temperature sensor 27, either a thermocouple type or a thermistertype, is constructed at the proximity of the electrode 9B (shown in FIG.6) to measure the tissue contact temperature when high frequency energyis delivered. A temperature sensing wire 28 from the thermocouple orthermister is connected to one of the contact pins of the connector 8and externally connected to a transducer and to a temperature controller29. The temperature reading is thereafter relayed to a closed-loopcontrol mechanism to adjust the high frequency energy output. The highfrequency energy delivered is thus controlled by the temperature sensorreading or by a pre-programmed control algorithm.

This invention also discloses a method for repairing a valvular annulusdefect, the method comprising injecting a heat shapeable biomaterialformulated for in vivo administration by injection via a catheter systemat a site of the valvular annulus defect; and applying heat sufficientto shape the biomaterial and immobilize the biomaterial at about theannulus defect.

The term “shapeable biomaterial” as used herein is intended to mean anybiocompatible material that changes its shape, size, or configuration atan elevated temperature without significantly affecting its compositionor structure. The shaping of a shapeable biomaterial is usuallyaccomplished by applying moderate energy. For example, a crosslinkedmaterial is structurally different from a non-crosslinked counterpartand is not considered as a shaped material. The elevated temperature inthis invention may range from about 39° C. to about 45° or higher,wherein the heat is below a temperature for effecting crosslinking ofthe biomaterial.

The biomaterial may comprise a matrix of collagen, a connective tissueprotein comprising naturally secreted extracellular matrix, a heatshapeable polymer, or the like.

The term “matrix of collagen” as used herein is intended to mean anycollagen that is injectable through a suitable applicator, such as acatheter, a cannula, a needle, a syringe, or a tubular apparatus. Thematrix of collagen as a shapeable biomaterial of the present inventionmay comprise collagen in a form of liquid, colloid, semi-solid,suspended particulate, gel, paste, combination thereof, and the like.Devore in PCT WO 00/47130 discloses injectable collagen-based systemdefining matrix of collagen, entire disclosure of which is incorporatedherein by reference.

The shapeable biomaterial may further comprise a pharmaceuticallyacceptable carrier for treating the annulus defect and a drug is loadedwith the pharmaceutically acceptable carrier, wherein the drug isselected from a group consisting of an anti-clotting agent, ananti-inflammatory agent, an anti-virus agent, an antibiotics, a tissuegrowth factor, an anesthetic agent, a regulator of angiogenesis, asteroid, and combination thereof.

The connective tissue protein comprising naturally secretedextracellular matrix as a shapeable biomaterial of the present inventionmay be biodegradable and has the ability to promote connective tissuedeposition, angiogenesis, and fibroplasia for repairing a tissue defect.U.S. Pat. No. 6,284,284 to Naughton discloses compositions for therepair of skin defects using natural human extracellular matrix byinjection, entire contents of which are incorporated herein byreference. Bandman et al. in U.S. Pat. No. 6,303,765 discloses humanextracellular matrix protein and polynucleotides which identify andencode the matrix protein, wherein the human extracellular matrixprotein and its polynucleotides may form a shapeable biomaterial of thepresent invention.

The shapeable polymer as a biomaterial in the present invention may alsocomprise biodegradable polymer and non-biodegradable polymer, includingprepolymer and polymer suspension. In one embodiment, the shapeablepolymer in this invention may be selected from a group consisting ofsilicone, polyurethane, polyamide, polyester, polystyrene,polypropylene, polyacrylate, polyvinyl, polycarbonate,polytetrafluoroethylene, poly (1-lactic acid), poly (d, 1-lactideglycolide) copolymer, poly(orthoester), polycaprolactone, poly(hydroxybutyrate/hydroxyvaleerate) copolymer, nitrocellulose compound,polyglycolic acid, cellulose, gelatin, dextran, and combination thereof.

Slepian et al. in U.S. Pat. No. 5,947,977 discloses a novel process forpaving or sealing the interior surface of a tissue lumen by entering theinterior of the tissue lumen and applying a polymer to the interiorsurface of the tissue lumen. Slepian et al. further discloses that thepolymer can be delivered to the lumen as a monomer or prepolymersolution, or as an at least partially preformed layer on an expansiblemember, the entire contents of which are incorporated herein byreference. The polymer as disclosed may be suitable as a component ofthe shapeable biomaterial of the present invention.

A method for joining or restructuring tissue consisting of providing apreformed sheet or film which fuses to tissue upon the application ofenergy is disclosed in U.S. Pat. No. 5,669,934, entire contents of whichare incorporated herein by reference. Thus, the protein elements of thetissue and the collagen filler material can be melted or denatured,mixed or combined, fused and then cooled to form a weld joint. However,the heat shapeable biomaterial of the present invention may comprisecollagen matrix configured and adapted for in vivo administration byinjection via a catheter system at a site of the tissue defect; andapplying heat sufficient to shape the biomaterial and immobilize thebiomaterial at about the tissue defect, but not to weld the tissue.

An injectable bulking agent composed of microspheres of crosslinkeddextran suspended in a carrier gel of stabilized hyaluronic acid ismarketed by Q-Med AB (Uppsala, Sweden). In one embodiment ofapplications, this dextran product may be injected submucosally in theurinary bladder in close proximity to the ureteral orifice. Theinjection of dextran creates increased tissue bulk, thereby providingcoaptation of the distal ureter during filling and contraction of thebladder. The dextran microspheres are gradually surrounded by body's ownconnective tissue, which provides the final bulking effect. The heatshapeable polymer of the present invention may comprise dextranconfigured and adapted for in vivo administration by injection via acatheter system at a site of the tissue defect; and applying heatsufficient to shape the biomaterial and immobilize the biomaterial atabout the tissue defect.

Sinofsky et al. in U.S. Pat. No. 5,100,429 discloses an uncured orpartially cured, collagen-based material delivered to a selected site ina blood vessel and is crosslinked to form an endoluminal stent, entirecontents of which are incorporated herein by reference. Thecollagen-based material as disclosed may form a component of theshapeable biomaterial of the present invention. Edwards in PCT WO01/52930 discloses a method and system for shrinking dilatations of abody, removing excess, weak or diseased tissues and strengtheningremaining tissue of the lumen walls, the entire contents of which areincorporated herein by reference. However, Edwards does not disclose amethod for repairing a tissue defect comprising: injecting a heatshapeable biomaterial formulated for in vivo administration by injectionvia a percutaneous delivery system at a site of the tissue defect; andapplying heat to the biomaterial and a portion of the tissue defectadapted for shaping the biomaterial, the heat being below a temperaturesufficient for effecting crosslinking of the biomaterial and the portionof the tissue defect.

Therefore, it is a further embodiment to provide a method for repairinga tissue defect comprising: injecting a heat shapeable biomaterialformulated for in vivo administration by injection via a percutaneousdelivery system at a site of the tissue defect; and applying heat to thebiomaterial and a portion of the tissue defect adapted for shaping thebiomaterial, the heat being below a temperature sufficient for effectingcrosslinking of the biomaterial and the portion of the tissue defect,the tissue defect may comprise vulnerable plaque, calcified tissue, orother lesions of atherosclerosis.

From the foregoing, it should now be appreciated that an improvedcatheter system and methods having electrode element means and highfrequency current energy intended for tightening and stabilizing thetissue of an annular organ structure has been disclosed. It is generallyapplicable for repairing an annular organ structure of a heart valve, anannular organ structure of a venous valve, a valve leaflet, chordaetendinae, papillary muscles, and the like. While the invention has beendescribed with reference to a specific embodiment, the description isillustrative of the invention and is not to be construed as limiting theinvention. Various modifications and applications may occur to thoseskilled in the art without departing from the true spirit and scope ofthe invention as described by the appended claims.

What is claimed is:
 1. A catheter system for repairing an annular organstructure comprising: a flexible catheter shaft having a distal tipsection, a distal end, a proximal end, and at least one lumen extendingbetween the distal end and the proximal end; a flexible tissue-contactormember located at the distal tip section and inside the at least onelumen of said catheter shaft for contacting an inner wall of the annularorgan structure, wherein said tissue-contactor member is deployable outof the at least one lumen by a tissue-contactor deployment mechanism andis expandable upon deployment configured to have a narrow middle regionbetween an enlarged distal region and an enlarged proximal regionsuitable for compressively sandwiching said inner wall of the annularorgan structure; a plurality of electrode elements located at aperiphery of the middle region of said tissue-contractor member suitablefor contacting said inner wall of the annular organ structure; a handleattached to the proximal end of the catheter shaft, wherein the handlecomprises the tissue-contactor deployment mechanism; and a highfrequency current generator, wherein an electrical conductor means fortransmitting high frequency current to said electrode elements isprovided.
 2. The catheter system of claim 1, wherein the electrodeelements are made of conductive elastomer material.
 3. The cater systemof claim 2, wherein the tissue-contactor member is a biocompatibleballoon whose fabricating material is selected from the group consistingof silicone, latex, polyurethane, fluoro-elastomer, polypropylene,polyethylene, polyethylene terephthalate, nylon, and a combinationthereof.
 4. The catheter system of claim 3, wherein the tissue-contactormember comprises a distal end, a proximal end and a plurality of openchannels therebetween for a fluid to pass from the proximal end of saidtissue-contactor member to the distal end of said tissue-contactormember.
 5. The catheter system of claim 1, wherein the annular organstructure is selected from the group consisting of a mitral valve, atricuspid valve, a pulmonary valve, an aortic valve, and a venous valve.6. The catheter system of claim 1, wherein the annular organ structureis a sphincter annulus.
 7. The catheter system of claim 1 furthercomprising at least one temperature sensor mounted at one of theelectrode elements adapted for measuring temperature of the inner wallof the annular organ structure.
 8. The catheter system of claim 5 or 6,wherein said tissue-contactor member comprises an expandable constructwith a plurality of expandable members enabling said tissue-contactormember to expand radially upon deployment, and wherein saidtissue-contactor member further comprises a first expandable balloonlocated proximal of the expandable construct suitable for positioningsaid balloon at an upstream side of the valvular annulus and a secondexpandable balloon located distal of the expandable construct adaptedfor compressively sandwiching the inner wall of said annular organstructure between the expanded first balloon and the expanded secondballoon.
 9. A method for operating a catheter system for repairing anannulus comprising compressively sandwiching said annulus by atissue-contactor member having electrode elements and delivering highfrequency energy at or near said annulus through said electrodeelements, wherein the catheter system comprises a flexible cathetershaft having a distal tip section, a distal end, a proximal end, and atleast one lumen extending between the distal end and the proximal end; aflexible tissue-contactor member located at the distal tip section andinside the at least one lumen of said catheter shaft for contacting aninner wall of the annulus, wherein said tissue-contactor member isdeployable out of the at least one lumen by a tissue-contactordeployment mechanism and is expandable upon deployment configured tohave a narrow middle region between an enlarged distal region and anenlarged proximal region suitable for compressively sandwiching saidinner wall of the annulus; a plurality of electrode elements located atthe periphery of the tissue-contactor member suitable for contactingsaid inner wall of the annulus; a handle attached to the proximal end ofthe catheter shaft, wherein the handle comprises the tissue-contactordeployment mechanism; and a high frequency current generator, wherein anelectrical conductor means for transmitting high frequency current tosaid electrode elements is provided; the method comprising: (a)introducing the catheter system through a bodily opening to an annulus;(b) deploying the tissue-contactor member of the catheter shaft at aboutthe inner wall of the annulus; (c) postioning the electrode elements soas to enable the electrode elements compressively sandwiching said innerwall of the annulus; and (d) applying high frequency current through theelectrical conductor means to the electrode elements for repairing theannulus.
 10. The method for operating a catheter system for repairing anannulus of claim 9, wherein the tissue-contactor member is abiocompatible balloon whose fabricating material is selected from thegroup consisting of silicone, latex, polyurethane, fluoro-elastomer,polypropylene, polyethylene, polyethylene terephthalate, nylon, and acombination thereof.
 11. The method for operating a catheter system forrepairing an annulus of claim 9, wherein the electrode elements are madeof conductive elastomer material.
 12. The method for operating acatheter system for repairing an annulus of claim 9, wherein the annulusis selected from the group consisting of a mitral valve, a tricuspidvalve, a pulmonary valve, an aortic valve, and a venous valve.
 13. Themethod for operating a catheter system for repairing an annulus of claim9, wherein the tissue-contactor member comprises a distal end, aproximal end and a plurality of open channels therebetween for a fluidto pass from the proximal end of said tissue-contactor member to thedistal end of said tissue-contactor member.
 14. The method for operatinga catheter system for repairing an annulus of claim 9, wherein the highfrequency current is delivered to said plurality of electrodes in a modeselected from the group consisting of individual mode, pulsed mode,programmed mode, and simultaneous mode.
 15. The method for operating acatheter system for repairing an annulus of claim 9, wherein the highfrequency current is selected from the group consisting ofradiofrequency current, microwave current, ultrasound current, andcombination thereof.
 16. The method for operating a catheter system forrepairing an annulus of claim 9, wherein the tissue-contactor member isa biocompatible balloon whose fabricating material is selected from thegroup consisting of silicone, latex, polyurethane, fluoro-elastomer,polypropylene, polyethylene, polyethylene terephthalate, nylon, and acombination thereof.
 17. The method for operating a catheter system forrepairing an annulus of claim 9, wherein said tissue-contactor membercomprises a basket construct with a plurality of expandable membersenabling said tissue-contactor member to expand radially upondeployment, and wherein said tissue-contactor member further comprises afirst expandable balloon located proximal of the basket construct and asecond expandable balloon located distal of the basket construct adaptedfor compressively sandwiching the inner wall of said annulus between theexpanded first balloon and the expanded second balloon.
 18. The methodfor operating a catheter system for repairing an annulus of claim 9,wherein the annulus is a sphincter annulus.